mm-739 === Subject: Re: Internal Set Theory Uniqueness Principle > NelsonÕs theorem and proof can be extended to the \ following result. > Let P(u,v_1,....,v_k) be a formula in Internal Set Theory such that > the only occurrences of the predicate \ ŌstandardÕ in the formula are > in quanti\[CapitalThorn]ers of the type for all standard z in V or for some > standard z in V for some standard set V (V can differ from quanti\[CapitalThorn]er > to quanti\[CapitalThorn]er). If y_1, ..., y_k are standard, and there is a unique > x such that P(x,y_1,...,y_k) holds, the unique value of x is standard. > My question relates to what happens if for all standard z in V and > for some standard z in V are relaxed to for all standard z and > for some standard z. Is it still true that x must be standard? IÕm thinking this is true because it seems to me every external formula can be reduced to a weakly equivalent internal formula, with no proviso needed. Indeed, just as in logic, we can arrange to put the external formula into an equivalent prenex form, whose prenex is a sequence of internal and external quanti\[CapitalThorn]ers. Using the triviality and its dual that for all x commutes with for all standard x and then also using idealization to push the external generalizations to the left of the internal instantiations and the external instantiations to the left of the internal generaliztions (creating new internal quanti\[CapitalThorn]ers in the process), we can get an equivalent prenex formula all of whose external quanti\[CapitalThorn]ers precede its internal quanti\[CapitalThorn]ers. But the same argument that shows that transfer implies that any internal formula A is weakly equivalent to A_st also seems to show that given any internal formula in prenex form, standardizing an intitial segment of the prenex gives rise to a weakly equivalent formula. Indeed, to show this last part, just use induction on the length of the prenex segment and the fact that the transfer principle implies the statement that you get if you replace any subset of the external generalizations that occur in the prenex of an instance of the transfer axiom with external instantiations. I have my doubts, though, about my being correct, for if I am so, Why did Nelson bother doing things the way he did, being careful to push the external generalizations to the left of the external instantions (using the logic trick that you can do this by de\[CapitalThorn]ning functions (which inelegantly require domains of de\[CapitalThorn]nition)), unless it be necessary? Do you see a mistake somewhere in my reasoning? I refer not to NelsonÕs original paper, but to the chapter \ of his un\[CapitalThorn]nished book at http://www.math.princeton.edu/~nelson/books.html . === Subject: Re: Internal Set Theory Uniqueness Principle >> NelsonÕs theorem and proof can be extended to the following result. >> Let P(u,v_1,....,v_k) be a formula in Internal Set Theory such that >> the only occurrences of the predicate \ ŌstandardÕ in the formula are >> in quanti\[CapitalThorn]ers of the type for all standard z in V or for some >> standard z in V for some standard set V (V can differ from quanti\[CapitalThorn]er >> to quanti\[CapitalThorn]er). If y_1, ..., y_k are standard, and there is a unique >> x such that P(x,y_1,...,y_k) holds, the unique value of x is standard. >> My question relates to what happens if for all standard z in V and >> for some standard z in V are relaxed to for all standard z and >> for some standard z. Is it still true that x must be standard? >IÕm thinking this is true because it seems to me every external formula can >be reduced to a weakly equivalent internal formula, with no proviso needed. >Indeed, just as in logic, we can arrange to put the external formula into an >equivalent prenex form, whose prenex is a sequence of internal and >external quanti\[CapitalThorn]ers. Using the triviality and its dual that for all x >commutes with for all standard x and then also using idealization to push >the external generalizations to the left of the internal instantiations and >the external instantiations to the left of the internal generaliztions >(creating new internal quanti\[CapitalThorn]ers in the process), we can get an equivalent >prenex formula all of whose external quanti\[CapitalThorn]ers precede its internal >quanti\[CapitalThorn]ers. The dif\[CapitalThorn]culty with this is that it canÕt always \ be made to work. If you have A r E st s A st t Q(r,s,t,...) or E r A st s E st t Q(r,s,t,...), where ŌAÕ denotes for all, \ ŌEÕ denotes there exists, \ ŌstÕ denotes standard, and Q(r,s,t,...) is a formula in IST, then idealization canÕt be invoked since A st t Q(r,s,t...) and E st t Q(r,s,t,...) are external formulae. This makes it dif\[CapitalThorn]cult (impossible?) to drag all the quanti\[CapitalThorn]ers over standard quantities to the outside where transfer can be invoked. I have a copy of a paper by V. Kanovei where he claims to have a formula in IST which canÕt be reduced to a formula in ZFC, \ speci\[CapitalThorn]cally A F [(F is a function with domain Z and A st n in Z (F(n) is standard)) => E st G (G is a function with domain Z and A st n in Z (F(n) = G(n))]. >But the same argument that shows that transfer implies that any >internal formula A is weakly equivalent to A_st also seems to show that >given any internal formula in prenex form, standardizing an intitial segment >of the prenex gives rise to a weakly equivalent formula. Indeed, to show >this last part, just use induction on the length of the prenex segment and >the fact that the transfer principle implies the statement that you get if >you replace any subset of the external generalizations that occur in the >prenex of an instance of the transfer axiom with external instantiations. I >have my doubts, though, about my being correct, for if I am so, Why did >Nelson bother doing things the way he did, being careful to push the >external generalizations to the left of the external instantions (using the >logic trick that you can do this by de\[CapitalThorn]ning functions (which inelegantly >require domains of de\[CapitalThorn]nition)), unless it be necessary? Do you see a >mistake somewhere in my reasoning? As I remarked above, we canÕt handle cases like A r E st s A st t or E r A st s E st t. In the case where we have A r E st s in V A st t in W Q(r,s,t,...) or E r A st s in V E st t in W Q(r,s,t,...), where V and W are standard and Q(r,s,t,...) is an internal formula, it is easy to handle since the A st and the E st can swapped in the manner that you mention above, and then idealization can be applied. >I refer not to NelsonÕs original paper, but to the chapter of his un\[CapitalThorn]nished >book at http://www.math.princeton.edu/~nelson/books.html . David And all dared to brave unknown terrors, to do mighty deeds, to boldly split in\[CapitalThorn]nitives that no man had split before - and thus was the Empire forged. ----- === Subject: Re: Internal Set Theory Uniqueness Principle > >require domains of de\[CapitalThorn]nition)), unless it be necessary? Do you see a > >mistake somewhere in my reasoning? > As I remarked above, we canÕt handle cases like A r E st s A st t or > E r A st s E st t. In the case where we have A r E st s in V A st t in W > Q(r,s,t,...) or E r A st s in V E st t in W Q(r,s,t,...), where V and > W are standard and Q(r,s,t,...) is an internal formula, it is easy to > handle since the A st and the E st can swapped in the manner that you > mention above, and then idealization can be applied. > >I refer not to NelsonÕs original paper, but to the \ chapter of his un\[CapitalThorn]nished > >book at http://www.math.princeton.edu/~nelson/books.html . > David > And all dared to brave unknown terrors, to do mighty deeds, > to boldly split in\[CapitalThorn]nitives that no man had split before - > and thus was the Empire forged. > ----- OK, yes, now I see. I stupidly forgot that idealization required an internal formula. I suppose NelsonÕs algorithm works because a sequence of n external generalizatons is like an external generalization of a sequence with n terms, which when between an internal formula and an internal instantiation can jump over the internal instantiation because of idealization. === Subject: Re: Internal Set Theory Uniqueness Principle >> >require domains of de\[CapitalThorn]nition)), unless it be necessary? Do you see a >> >mistake somewhere in my reasoning? >> As I remarked above, we canÕt handle cases like A r E st \ s A st t or >> E r A st s E st t. In the case where we have A r E st s in V A st t in >> Q(r,s,t,...) or E r A st s in V E st t in W Q(r,s,t,...), where V and >> W are standard and Q(r,s,t,...) is an internal formula, it is easy to >> handle since the A st and the E st can swapped in the manner that you >> mention above, and then idealization can be applied. >> >I refer not to NelsonÕs original paper, but to the chapter of his >un\[CapitalThorn]nished >> >book at http://www.math.princeton.edu/~nelson/books.html . >> David >> And all dared to brave unknown terrors, to do mighty deeds, >> to boldly split in\[CapitalThorn]nitives that no man had split before - >> and thus was the Empire forged. >> ----- >OK, yes, now I see. I stupidly forgot that idealization required an internal >formula. I made the same mistake earlier when I attempted a proof in the general case. I managed to get to the point where I had concluded that the unique value under the general conditions must be standard, and then when I went back, I realized that I had been applying idealization willy nilly to external formulae, and I had to throw out all of my work. >I suppose NelsonÕs algorithm works because a sequence of n external >generalizatons is like an external generalization of a sequence with n >terms, ThatÕs correct. The statement that a set is such a sequence, and that its components are speci\[CapitalThorn]ed sets is internal, and so is allowable. >which when between an internal formula and an internal instantiation >can jump over the internal instantiation because of idealization. David Men were real men, women were real women, and small furry creatures from Alpha Centauri were real small furry creatures from Alpha Centauri. ----- === Subject: Re: 3 Questions on Z[sqrt(n)] days. My association with the Department is that of an alumnus. >>>If Z[sqrt(n)] is _not_ the ring of algebraic integers in Q(sqrt(n)) >>>then it is not integrally closed, and so cannot be a UFD. >>>So for the purpose of your query, the only cases of interest >>>are when Z[sqrt(n)] _is_ the ring of algebraic integers, >>>ie when n is square-free and n is not = 1 mod 4. >> Well, there are cases where Z[sqrt(n)] ->is<- the ring of >> integers of Q(sqrt(n)), but n is not square free. >IÕm sure you are right, as you usually are! Hmmm... Maybe not. I think my error was to confuse the fact that Q(sqrt(n)) would equal Q(sqrt(m)), and conclude incorrectly that Z[sqrt(n)] would equal Z[sqrt(m)], where we write n = d^2*m with m square free. I think you were right. Sorry about that... (And just a few hours ago, in another newsgroup, I said that 1976+30 = 1996... ) -- ItÕs not denial. IÕm just very selective \ about what I accept as reality. --- Calvin (Calvin and Hobbes) Arturo Magidin magidin@math.berkeley.edu === Subject: Polynomial sequence Does anyone recognize this sequence of polynomials (over F_2). 1 x x^2+x+1 x^3 x^4+x^3+1 x^5+x^3+x x^6+x^5+x^4+x^3+x^2+x+1 x^7 x^8+x^7+1 etc. Bart === Subject: Re: Polynomial sequence > Does anyone recognize this sequence of polynomials > (over F_2). > x^2+x+1 > x^3 > x^4+x^3+1 > x^5+x^3+x > x^6+x^5+x^4+x^3+x^2+x+1 > x^7 > x^8+x^7+1 > etc. f_n = (x + 1) f_(n - 1) + 1? -- Gerry Myerson (gerry@maths.mq.edi.ai) (i -> u for email) === Subject: Re: Polynomial sequence >> Does anyone recognize this sequence of polynomials >> (over F_2). >> 1 >> x >> x^2+x+1 >> x^3 >> x^4+x^3+1 >> x^5+x^3+x >> x^6+x^5+x^4+x^3+x^2+x+1 >> x^7 >> x^8+x^7+1 >> etc. >f_n = (x + 1) f_(n - 1) + 1? aka n (x+1) - 1 f = ---------- n x Using the Lucas Correspondence Theorem http://mathworld.wolfram.com/LucasCorrespondenceTheorem.html which is proven more generally for multinomials at http://www.whim.org/nebula/math/lucascorrespondence.html it is easy to compute these polynomials. Let Ō&Õ \ be the bitwise ŌandÕ operator. Then, for m > 0, the coef\[CapitalThorn]cient of x^{m-1} in f_n is 1 iff n & m = m. This is why f_{2^n} has only one term, x^{2^n-1}, while all 2^n-1 terms appear in f_{2^n-1}. For example, knowing that 100 = 1100100 base 2, we get that 99 95 67 63 35 31 3 f = x + x + x + x + x + x + x 100 since 1 more than each exponent has the binary expansion 100 = 1100100 96 = 1100000 68 = 1000100 64 = 1000000 36 = 100100 32 = 100000 4 = 100 That is, a 1 appears in the bits of exponent+1 only where a 1 appears in the bits of n. Rob Johnson take out the trash before replying === Subject: Re: Polynomial sequence Originator: anno4000@lublin.zrz.tu-berlin.de (Anno Siegel) > >> Does anyone recognize this sequence of polynomials > >> (over F_2). > >> > >> 1 > >> > >> x > >> > >> x^2+x+1 > >> > >> x^3 > >> > >> x^4+x^3+1 > >> > >> x^5+x^3+x > >> > >> x^6+x^5+x^4+x^3+x^2+x+1 > >> > >> x^7 > >> > >> x^8+x^7+1 > >> > >> etc. > >f_n = (x + 1) f_(n - 1) + 1? > aka > n > (x+1) - 1 > f = ---------- > n x > Using the Lucas Correspondence Theorem > http://mathworld.wolfram.com/LucasCorrespondenceTheorem.html > which is proven more generally for multinomials at > http://www.whim.org/nebula/math/lucascorrespondence.html > it is easy to compute these polynomials. Let \ Ō&Õ be the bitwise ŌandÕ > operator. Then, for m > 0, the coef\[CapitalThorn]cient of x^{m-1} in f_n is 1 iff > n & m = m. This is why f_{2^n} has only one term, x^{2^n-1}, while all > 2^n-1 terms appear in f_{2^n-1}. > For example, knowing that 100 = 1100100 base 2, we get that > 99 95 67 63 35 31 3 > f = x + x + x + x + x + x + x > 100 > since 1 more than each exponent has the binary expansion > 100 = 1100100 > 96 = 1100000 > 68 = 1000100 > 64 = 1000000 > 36 = 100100 > 32 = 100000 > 4 = 100 > That is, a 1 appears in the bits of exponent+1 only where a 1 appears in > the bits of n. This sequence can be generated by starting with k = m = 100, then setting k = (k - 1) & m until it vanishes. Anno === Subject: Re: Polynomial sequence >> Does anyone recognize this sequence of polynomials >> (over F_2). >> 1 >> x >> x^2+x+1 >> x^3 >> x^4+x^3+1 >> x^5+x^3+x >> x^6+x^5+x^4+x^3+x^2+x+1 >> x^7 >> x^8+x^7+1 >> etc. >f_n = (x + 1) f_(n - 1) + 1? ... and thus with f_0 = 1, f_n = ((x+1)^(n+1)-1)/x. Note also that (n choose m) = 1 mod 2 iff each binary digit of n is 1 whenever the corresponding binary digit of m is 1. Thus e.g since 10 = 1010_2, (10 choose m) mod 2 = 1 only for m = 0, 2, 8, and 10. Corresponding to this, f_9 = x^9 + x^7 + x^1. Robert Israel israel@math.ubc.ca Department of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 === Subject: Re: Polynomial sequence >>>Does anyone recognize this sequence of polynomials >>>(over F_2). >>>1 >>>x >>>x^2+x+1 >>>x^3 >>>x^4+x^3+1 >>>x^5+x^3+x >>>x^6+x^5+x^4+x^3+x^2+x+1 >>>x^7 >>>x^8+x^7+1 >>>etc. >>f_n = (x + 1) f_(n - 1) + 1? > ... and thus with f_0 = 1, f_n = ((x+1)^(n+1)-1)/x. > Note also that (n choose m) = 1 mod 2 iff each binary digit of n > is 1 whenever the corresponding binary digit of m is 1. Thus > e.g since 10 = 1010_2, (10 choose m) mod 2 = 1 only for m = 0, 2, 8, > and 10. Corresponding to this, f_9 = x^9 + x^7 + x^1. I spotted the same relation last night by sketching out a grid of the coef\[CapitalThorn]cients and noticing it represented a slightly clipped sierpinksi gasket. Then if you know about pascals triangle mod 2 giving you the gasket you can see the link. Can I ask the original poster, from where did they pull these polynomials originally? alex === Subject: Re: Polynomial sequence >> ... and thus with f_0 = 1, f_n = ((x+1)^(n+1)-1)/x. >> Note also that (n choose m) = 1 mod 2 iff each binary digit of n >> is 1 whenever the corresponding binary digit of m is 1. Thus >> e.g since 10 = 1010_2, (10 choose m) mod 2 = 1 only for m = 0, 2, 8, >> and 10. Corresponding to this, f_9 = x^9 + x^7 + x^1. > I spotted the same relation last night by sketching out a grid of the > coef\[CapitalThorn]cients and noticing it represented a slightly clipped sierpinksi > gasket. Then if you know about pascals triangle mod 2 giving you the > gasket you can see the link. > Can I ask the original poster, from where did they pull these > polynomials originally? I was noticing that if 2^k <= n < 2^{k+1}, then f_n = x^{2^k}f_m + x^{2^k-1} + f_m Where m=n-2^k. I was treating a binary number as sequence b_n and looking at its Z-transform X(b)(x). By the shift x->x+1, I got the (shorter) polynomials f_n and noticed the above. (Just looking at the numerators of X(b).) I was mostly wondering if this was a named or a studied sequence. E.g., are they orthogonal in any sense? Bart === Subject: The Ōchain of shadowsÕ Please look at the attached pdf http://www.geocities.com/complementarytheory/Roots-Chain.pdf . By this model we can see that 1 is the shadow of 2 and 2 is the shadow of 3. I think that we can conclude that 3 is the shadow of 4 .. and so on. In short, I am talking about roots which each one of them is the diagonal of its dimension level, where each n_dim diagonal is the shadow of [i:f3563246cc][b:f3563246cc]n[/b:f3563246cc][/i:f3563246cc]+1 _dim diagonal. We have a chain of shadows between in\[CapitalThorn]nitely many diagonals \ in |[b:f3563246cc]N[/b:f3563246cc]| dimension levels. Do you think that this Chain of Shadows has any mathematical/physical meaning? ------------------------------------------------------------- --------------- ------------ Let us say that The chain of shadows is a conjuncture. Is there a possibility that there is no such a thing like a diagonal, in symmetrical elements (like a square in 2-d and a cube in 3-d), which have more then 3 dimensions? For example in 1-dim any line-segment of length 1 is its own diagonal, but in 2-dim and 3-dim the diagonal is the result of the of its dimension level, and we get an irrational number, which is different then the 1-dim case. In 4-dim we again get a natural number as the result of the diagonal length. In short, since in all cases we are talking about a diagonal (which is the root of its dimension level), then to disprove my conjuncture we have: [b:f3563246cc]1)[/b:f3563246cc] To show that there is a clear way to conclude that diagonals which belong to dimension levels that are > 3, are not necessarily the root of their dimension. [b:f3563246cc]2)[/b:f3563246cc] To show that there are dimensions > 3 without diagonals. If you have more ideas of how to disprove my conjuncture, then Ill be glad to know them. Here is again my diagram: http://www.geocities.com/complementarytheory/Roots-Chain.pdf ------------------------------------------------------------- --------------- ------------------ Maybe these facts are aslo related to this conjuncture. [u:f3563246cc][b:f3563246cc]Square Numbers[/b:f3563246cc][/u:f3563246cc] ([url]http://www.krysstal.com/numbers.html[/url]) Square Numbers are integers that are the square of smaller integers. For example 4 is 22 and 9 is 32 so the \[CapitalThorn]rst few square numbers are: 1 4 9 16 25 36 49 64 81 100 121 144 169 Note that the sequence of square numbers alternates between odd and even. Another interesting fact is that this series of square numbers can be produced by adding successive odd numbers. For example, the sum of the \[CapitalThorn]rst two odd numbers (1, 3) is 1 + 3 = 4 (a square number). The sum of the \[CapitalThorn]rst three odd numbers (1, 3, 5) is 9 (another sqauare). This is shown in the table below: 1 = 1 1 + 3 = 4 1 + 3 + 5 = 9 1 + 3 + 5 + 7 = 16 1 + 3 + 5 + 7 + 9 = 25 1 + 3 + 5 + 7 + 9 + 11 = 36 1 + 3 + 5 + 7 + 9 + 11 + 13 = 49 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 = 64 .. === Subject: Re: The Ōchain of shadowsÕ complementarytheory@yahoo-dot-com.no-spam.invalid (Doron Shadmi) > Please look at the attached pdf > http://www.geocities.com/complementarytheory/Roots-Chain.pdf > .... > In short, I am talking about roots which each one of them is the > diagonal of its dimension level.... YouÕre talking about the diagonal of an n-dimensional unit hypercube or measure polytope. Its vertices can be given coordinates (1,0,0,...,0), (0,1,0,...,)), (0,0,1,...,)), ...... (0,0,0,...,1), and the n-dimensional analogue of the so-called Theorem of Pythagoras gives the length of its diagonal as sqrt(1^2 + 1^2 + ... + 1^2) = sqrt(n) as you thought. It may be easier to follow what IÕve just written if you \ \[CapitalThorn]rst look at the special cases n = 2 and n = 3. > .... > Another interesting fact is that this series of square numbers can be > produced by adding successive odd numbers. For example, the sum of > the \[CapitalThorn]rst two odd numbers (1, 3) is 1 + 3 = 4 (a square number). The > sum of the \[CapitalThorn]rst three odd numbers (1, 3, 5) is 9 (another square).... Yes indeed. That fact also interested some Greek mathematicians of the 5th century B.C., who represented it by a pattern of pebbles like this: * | * | * | * | __| | | | * * | * | * | ______| | | * * * | * | __________| | * * * * | etc. ______________| Can you see how each odd number borders a square to give a larger square? Those early Greek mathematicians used such pebble patterns to picture several properties of natural numbers. Ken Pledger. === Subject: Re: The Ōchain of shadowsÕ > .... Its vertices can be given coordinates > (1,0,0,...,0), (0,1,0,...,)), (0,0,1,...,)), ...... (0,0,0,...,1), > .... Too much of the shift key. :-( Those coordinates should have been (1,0,0,...,0), (0,1,0,...,0), (0,0,1,...,0), ...... (0,0,0,...,1). Ken Pledger. === Subject: Re: continuity of norm function in R^n >> [...] >> >(although my \[CapitalThorn]eld is nuclear medicine, really). >> keen. iÕve read that if i take a few milligrams of plutonium my >> pain will go away in at most a few days. been wondering where >> to go for a second opinion... [plutonium isnÕt addictive, is it?] >As an evidence based medicine af\[CapitalThorn]cionado I have to tell you that I >donÕt know about any randomized controlled trial of plutonium for this >indication. A plutonium bomb might work, though: most people stop >complaining after a bomb is dropped on their head. huh. iÕm tempted to ask if you could get me one of those, \ but Ashcroft might not think it was funny... ************************ David C. Ullrich sorry about the inelegant formatting - typing one-handed for a few weeks... === Subject: Re: Arctan >> Hi all, >> Is the arctan function the same as appears on my scienti\[CapitalThorn]c calc. as >> tan^-1 or is that inverse tan? Or is inverse tan the same as arctan? >> Sorry if thatÕs unclear. IOW, does a key marked tan^-1 mean arctan? >Those all mean the same thing. >The -1 superscript in mathematics often means inverse, >and arctan is another name for the same thing. Sheesh. I did all this at school, but itÕs a *looonnnnnnggggg* time ago. :-( -- What is now proved was once only imaginÕd. - William Blake, 1793. === Subject: Re: Arctan Yes, it is. Or, inverse cosine. -- Gerry Myerson (gerry@maths.mq.edi.ai) (i -> u for email) === Subject: Re: Prime counting algorithms, speculation <> > holy cow, youÕre back to claiming itÕs \ -fast- compared to existing > methods? you really donÕt recall anything that happened \ the last > time you said this, right? We had fun last time. http://home.earthlink.net/~ewill3/math/primecounters/ index.html